The invention relates to a method for finding the position of a vehicle on a carriageway and to an apparatus therefor. Furthermore, the invention relates to an automobile having such an apparatus.
Electronic navigation systems assist a vehicle driver in driving his vehicle on a suitable route from a starting location to a destination. In this case, the global position of the vehicle is usually ascertained by a satellite signal sensor, e.g. a GPS (global positioning system) sensor, and presented on a map on a monitor. The vehicle is positioned on the schematically presented road by virtue of the GPS position in combination with suitable map matching methods. The reason is that the precision of the position finding in the vehicle by the satellite navigation is only approximately 20 m, which means that the vehicle position on the carriageway cannot be indicated with lane precision, for example. The number of lanes on the carriageway which are to be expected for the respective position is read from the digital navigation map, for example. For this purpose, the digital map comprises what are known as map attributes, which provide information about junctions, lane markings, road signs, etc. For turn-off maneuvers, it is thus possible to indicate the target lane, for example, to the driver. Besides the map presentation on a monitor, there is usually additionally a voice announcement.
DE 10 2009 008 959 A1 discloses a driver assistance system which combines a wide variety of information in order to assist a driver in vehicle navigation. To this end, satellite signals, vehicle sensor signals, ambient sensor data and traffic telematics information are merged in order to indicate the vehicle position with a higher level of precision. As part of map verification these data are compared with a stored digital map and are used to find the actual vehicle position.
DE 10 2008 053 531 A1 discloses a method for rating data from a digital map, which method is based on dedicated map quality information or measurement data from an ambient sensor system. For the purpose of validating the map material, the number and profile of the lanes is recorded using a camera, for example. In addition, it is possible to detect objects e.g. guardrails, with radar sensors and to use this information for checking the map data.
DE 10 2008 021 380 A1 discloses a method for predicting the profile of a carriageway ahead of a vehicle.
In a carriageway section close to the vehicle, the profile of the carriageway is captured by a camera, with lane markings also being able to be recognized. A position recognition system makes it possible to establish that section of the carriageway on which the vehicle is located, and the driver assistance system then allows lane tracking. For a carriageway section remote from the vehicle, the carriageway profile is additionally extracted from a map, classified and taken into consideration by the driver assistance system.
DE 10 2006 040 334 A1 discloses a method which can be used to sense lane markings. The lane profile is described by using a plurality of sensor and information sources, e.g. GPS data, radar and video signals and digital maps. The motion of vehicles in front can also be captured and used for determining the lane. A mathematical method allows the lane to be reconstructed.
DE 103 49 631 A1 also discloses a driver assistance device which uses lane information. This information is obtained from the trajectory of other vehicles, the profile of carriageway edge boundaries, GPS data and the position of particular objects. In particular, image recording and analysis methods are used.
US 2008/00773322 A1 discloses a navigation apparatus for a vehicle. The navigation apparatus comprises a position finding device for finding the position and the direction of travel of the vehicle. Furthermore, the navigation apparatus comprises a lane recognition device. In addition, a device for carrying out a map matching method is provided.
WO 2009/098154 A1 describes the sensing of at least one object in the environment of a vehicle with a sensor. In this case, the position captured with the sensor is aligned with a satellite navigation system and a digital map.
Finally, JP 2004 205527 A discloses a navigation system for a vehicle which informs the driver of his position in a lane on a carriageway. The navigation system comprises a lane recognition device, a position finding device, a satellite based locating system and a digital map.